Merge pull request opencontainers#822 from imjasonh/patch-1

Add standard base image annotations

Author: vbatts

annotations.md

@@ -40,6 +40,15 @@ This specification defines the following annotation keys, intended for but not l
     ```
 * **org.opencontainers.image.title** Human-readable title of the image (string)
 * **org.opencontainers.image.description** Human-readable description of the software packaged in the image (string)
+* **org.opencontainers.image.base.digest** [Digest](descriptor.md#digests) of the image this image is based on (string)
+  * This SHOULD be the immediate image sharing zero-indexed layers with the image, such as from a Dockerfile `FROM` statement.
+  * This SHOULD NOT reference any other images used to generate the contents of the image (e.g., multi-stage Dockerfile builds).
+* **org.opencontainers.image.base.name** Image reference of the image this image is based on (string)
+  * This SHOULD be image references in the format defined by [distribution/distribution](https://github.com/distribution/distribution/blob/d0deff9cd6c2b8c82c6f3d1c713af51df099d07b/reference/reference.go).
+  * This SHOULD be a fully qualified reference name, without any assumed default registry. (e.g., `registry.example.com/my-org/my-image:tag` instead of `my-org/my-image:tag`).
+  * This SHOULD be the immediate image sharing zero-indexed layers with the image, such as from a Dockerfile `FROM` statement.
+  * This SHOULD NOT reference any other images used to generate the contents of the image (e.g., multi-stage Dockerfile builds).
+  * If the `image.base.name` annotation is specified, the `image.base.digest` annotation SHOULD be the digest of the manifest referenced by the `image.ref.name` annotation.
 
 ## Back-compatibility with Label Schema
 

specs-go/v1/annotations.go

@@ -53,4 +53,10 @@ const (
 
 	// AnnotationDescription is the annotation key for the human-readable description of the software packaged in the image.
 	AnnotationDescription = "org.opencontainers.image.description"
+
+	// AnnotationBaseImageDigest is the annotation key for the digest of the image's base image.
+	AnnotationBaseImageDigest = "org.opencontainers.image.base.digest"
+
+	// AnnotationBaseImageName is the annotation key for the image reference of the image's base image.
+	AnnotationBaseImageName = "org.opencontainers.image.base.name"
 )